The supercharged V8 engine in the SL 55 AMG was the founder member of Mercedes Benz’s 500 hp model range. The end result is awesome performance at low revs and phenomenal in-gear acceleration. The SL 55 AMG covers the sprint from 0 to 62.5 mph in just 4.7 seconds and reaches an electronically limited top speed of 155 mph. The engine is clean, too, as the AMG high performance exhaust system complies with EU-4 emissions standards.

The impressive engine powers the new SL 55 AMG to the top of the eight-cylinder roadster segment worldwide in terms of performance and torque.

The gearbox, (and that of the E 55 AMG), is an upgraded five-speed automatic system with racing style steering wheel gearshift buttons, with which the driver can operate the gears manually. The gearbox also includes the standard and winter settings, as on the SL 500.

A powerful braking system, designed by AMG to cope with the engine’s performance, gives the SL 55 AMG impressive stopping power. Using the Sensotronic Brake Control (SBC™) system pioneered in the SL 500, the AMG system (shared in the E 55 AMG) includes perforated, internally ventilated brake discs with eight-piston fixed callipers at the front, and four-piston fixed callipers at the rear. These callipers are painted silver, and bear a black AMG logo.

The Active Body Control (ABC) suspension and damping system, which eliminates body pitch and roll, has been upgraded by AMG to take into account the higher performance of the car, and uses a firmer set-up to improve handling.

Visually, the AMG Roadster can be spotted by several eye-catching features, including dynamic styling, striking AMG side skirts, partially darkened taillights, and four chromed AMG tailpipes. A diffuser-look rear apron includes a black rib-mesh grille, as fitted to the front air intake. Its sporty 18 inch multi-spoke alloy wheels were inspired by the awesome 612 hp CLK-GTR, of which 25 models were built for road use.

Inside the SL 55 AMG, the exclusive AMG integral sports seats are trimmed with special perforated leather, and include silver-plated AMG badging. The dash has high-quality sand cast-effect aluminium trim. The cockpit instruments have light-coloured dials ringed with dark grey, with silver symbol panels and red needles which emphasise the unique character of this high-performance roadster. The steering wheel was also developed by AMG, and incorporates gear shift buttons.

Passenger comfort is further enhanced by the automatic climate control system with a sun and pollutant sensor, memory function for the seats, steering wheel and exterior mirrors, and the Headlamp Assist light sensor which switches on the lights when it gets dark, or when driving through a tunnel. An anti-theft alarm, electronic throttle control and infrared remote control for the vario-roof are other special features included as standard in the new SL-Class.

Another improvement on the previous SL generation can be seen in the unique hi-tech equipment fitted as standard on the new SL 500 and SL 55 AMG. This includes leading-edge driving dynamics systems - such as SBC™ braking and Active Body Control (ABC) suspension - the innovative vario-roof, new head-thorax side-impact airbags and bi-xenon headlamps.

In fact, the SL-Class includes three world firsts amongst its impressive armoury of equipment. Its revolutionary head-thorax airbags were developed to provide side impact protection for occupants’ heads similar to that offered by curtain airbags in closed roof cars. The airbags, mounted in the door, expand upwards in the event of a severe side impact, in under 20 milliseconds. The head-thorax bags have a volume of 25 litres, and extend 170 – 240 millimetres further up the car than a traditional side bag.

The SL-Class was also the first production car to use electronic braking technology. SBC™ is the world’s first "brake-by-wire" system fitted to a road car. The brake pedal is connected electrically to the main brake cylinder (removing the need for a vacuum-powered brake booster) and a powerful microprocessor passes the braking information on to the hydraulically-activated brakes using electrical pulses. In order to maintain the driver’s "feel" for the brakes, a special simulator uses spring pressure and hydraulics to give pedal resistance.

SBC™ gives quicker reaction times than a conventional system, meaning shorter stopping distances –around three per cent quicker at 70 mph. In wet conditions SBC™ will gently apply the brakes to dry the discs, thus improving wet weather braking performance. The driver is unaware that the brakes are operated.

The third world debut is the three-section fully automatic vario-roof. Comprising an aluminium roof panel, strengthened C pillars, and a rear windscreen made of four millimetre thick safety glass, the entire opening or closing procedure takes just 16 seconds – compared with 25 seconds for the SLK-Class Roadster.

When opened or closed, the rear screen rotates to reduce the amount of boot space taken by the folded roof. The assembly employs 11 hydraulic cylinders. In order to make loading and unloading of the boot easier when the roof is open, the "Easy Pack" can raise the folded roof by 20 degrees.